You are requiring a bit to much.
A quote says find and marry a rich girl or a rich boy, and you will become rich.
Only one of many opportunity.
Lol..True..
If your father is poor it's not your fault, but if your father-in-law is poor then it is definitely your fault

So I would rather find a millionaire girl and would get happily married and happily rich

It is 100% true, this is maybe the hardest way to become rich, but is one of them.
And near nobody has that luck to become rich in this way that i said.